Floating sector seals



July 19, 1960 A. L. BURCHFIELD 2,945,681

momma SECTOR SEALS Filed April 19, 1956 3 Sheets-Sheet 1 AGENT July 19, 1960 A. L. BURCHFIELD 2,945,681

. FLOATING SECTOR SEALS Filed April 19, 1956 3 Sheets-Sheet 2 6 I INVENTOR.

. AGE/VI A. L. BURCHFIELD 2,945,681

FLOATING SECTOR SEALS July 19, 1960 3 Sheets-Sheet 5 Filed April 19, 1956 INVEN TOR. 4/04? 1 flafch //a iii FLOATING SECTORSEALS Arden L. Burchfield, WellsvilIe; N.Y., assignor toThe Air Preheater Corporation, New York, N.Y., a corporation of New York h h i V Filed Apr. 19, 1956, Ser.No. 579,258 9 Claims. 01. 251-1 9 The present invention relates to heat exchange apparatus and particularly to improved radial seals for use between a rotor and the enclosing housing ofja vertical type rotary regenerative air preheater. a r

In a rotary regenerative air preheater or the like, a cylindrical rotor has compartments carrying heat transfer elements which as the rotor turns are firstexposed to heating gases and ,then' disposed in an air passage to impart absorbed heat to the air passing therethrough. The rotor is surrounded by a housing having end'or sector plates formed with openings to permit the flow ofair and gas therethrough. To pevent'mingling of the two fluids radial partitions that form the rotor compartments are provided with radial seals that wipe against "the imperforate' portions of the end plates. :In order'to preclude by-passing .of gas and air around the'rotor through the clearance space between sides of the'rotor 'and the housingwithout contacting the heat transfer material, it is customaryto provide the rotor with cir'ctim =ferential seals that bear against a'stationary part offthe housing.

Usually air preheaters of the general type here referred to are subjected to a wide range of temperature variations which'res'ults 'in considerablethermal deformation of the preheater structure including the rotorshell and 'the radial partitions. "Since the radial sealing members are aflixed-tothe radial partitions. it is evident that thermal distortion partitions imparts similar distortion to the sealing members connected thereto; and it therefore becomes an object of this invention to provide a .radial sealing member mounted independent fro m 'the radial partitions and not subject to the thermal distortion thereof. 1

- The present invention will u understood upon consideration of thsrouawmg detaileddescription of an illustrative embodiment thereof whenread in conjunction with the accompanying drawings in which:

Figure 1 is a sectional elevation view in diagrammatic form of a'rotary regenerative air preheater embodying the invention.

Figure 2 is a perspective view on an enlarged scale of the sealing assembly.

Figures 3, 4, 5 and 6 illustrate similar views of modified forms of sealing means constructed according to this invention.

Figures 7 and 8 illustrate modifications of a sealing means as used at the lower end of a rotary regenerator.

In the drawings the numeral 10 designates a cylindrical housing for the rotor of a rotary air preheater which is enclosed at both ends by end or sector plates 19 apertured at 20, 21 (Figure 2)-to provide passage for the air and gas streams therethrough. Centrally positioned within the rotor housing is a rotor post 12 supporting a rotor 13 which is divided into wedge or sector shaped compartments by partitions 14 extending radially outward from the rotor post. The rotor is turned on its axis by a'motor connected thereto through suitable reduction gearing not shown. Each rotor compartment conpoint of ultimate usage.

tains regenerative heat transfer material 15 in the form of spaced metallic plates which first absorb heat from the hot gases entering the preheater, and then as the rotor turns slowly about its axis, the heated plates are moved into a stream of cold-air to impart heat thereto. a After passing over the heated plates and absorbing heat therefrom, the heated air is directed to any predetermined In order that the streams of gas and air do not bypass the heat transfersurfacein therotor by flowing through the. space between the rotor and the adjacent end plates, novel sealing means is-pro- .vided to bridge the space thereby precluding flow there- In accordance with the present invention the end plates '19 have attached to 'their inner imperforate surface floating wedge shaped sealing members 22. that are adapted to rub against the end edges 'of the radial partitions 14 as the rotor rotates about its axis. The floating sealing members are mounted to be axially movable relative to the ends of the radial partitions; and they are provided with biasing means whereby they are at all times biased into contact with the adjacent end edges of the rotating partitions 14. To prevent fluids from flowing through the space intermediate the fixed end plate 19 and the floating sealing member 22 special pivotable or extensible connections are arranged to bridge the space in the manner illustrated in'Figure 2. 1

In this form of the inventiona channel member 26 having an elongate flange 27 fastened to the underside of fixed end-plate 19 extends radially outward from the 1 rotor post 12 to the outer periphery of the fixed' end plate'19. The floating seal is formed with a hook portion 28 which is adapted to be positioned-in channel-26 with a shank portion 32 of hook 28 pivotable upon the edge'of the flange 34- Whereby the sealing member 22 is free. to move axially into contact with partitions 14.

The sealing channel 26 is closed at its ends by plates 26a thereby; enabling it to .contain a fluid to submerge the hook 28. The particular fluid used'isdependent to alarge extent upon the operating temperature of the device, therefore no attempt is here made to specify anyparticular-fluid; A staybar 29 removably'fastened to the plates 26a at oppositeends of the channel 26 permits easy assembly and disassemblyof the sealing unit.

In order :that the face ofthesealing means 22 may be held income with the end; surfaces of the rotating radial partitions. 'special biasingmeans may be employed. Figure 2'illustrates abasicform of biasing means 'comprising'one or more weights 31 on a positioning means 32. In Figure 4 a slightly diiferent form illustrates an adjustable spring in a housing 34 pressing against a plunger 35 acting directly against the upper surface of the floating sealing member 22. This spring device is mounted on the imperforate portion of the end plate 19 and since the plunger projects through the latter the spring pressure may be readily adjusted during operations of the preheater.

Figure 5 illustrates another variation in which a pressure responsive device 36 fixed to the underside of sector plate 19 may be expanded against the plate 22 to place a downward force thereon. The pressure to actuate this device is applied through a port 38 connected to any predetermined source of pressure.

In Figure 6 the force biasing the floating member 22 against the end edges of partitions 14 is derived from the high intensity magnet 42 positioned on the member 22. As the partitions 14 rotate past the underside of plate 22 the magnet is attracted to each successive partition.

Figures 7 and 8 illustrate variations in form which permit the use of these sealing devices in the space between the lower end plate and the adjacent end edges of the radial partitions. Here the channel members 46 rest 3 directly on the endplate-19and the sealing means is biased upward into contact with the partitions. In Figure 7 the biasing means comprises a lever having a fixed fulcrum resting on the lower end plate and one end 52 in'contact with the sealingmeansWhilethe other-end is adapted to receive a weight 53' adjustably mounted to be capable of varyingthe-upward force against the sealing means. In Figure 8'the upward biasing force acting against the sealing means is applied against floats 58 formed-along radially extending edges of the sealing member-'56. Here theupward force is supplied by the buoyancy of the floats '58 displacing fluid contained in channels 46.

The use ofsprings, pressurized bellows or magnetic devices could readily be applied to lower sealing means of thetype-shown'in Figures 7-and 8 without departing from the spirit of the invention, and it is intended that all matter contained in the foregoing description or shown in the accompanyingdrawings shall be-interpreted as illustrative only and notin a limiting sense.

What I claim is: V

1. Regenerative heat exchange apparatus having a rotor'including a;cylindrical shell joined to arotor post "by radial'pa'rtitions forming'compartrnentsthatcarry heat transfer material, a-housing-surrounding the rotor and providedopposite thelatter with end plates formed with circumferentiaIIy spacedapertures between imperforate portions-which permit theflow of heating gases-and air to and through the rotor; and sectionalsealing means pivotally supported along aradially extending edge thereof by the imperforate'portions'of' the endplates adapted toprecludefluid flow between circumferentially spaced apertures.

2. Regenerative heat exchange apparatus as defined'in claim 1 wherein the sealing meansadjacent the upper end plate thereof is provided with variable weights disposed to bias the sealing means into contact with the: end faces of adjacent'radial partitions. v V

3. Regenerative heat exchange'apparatusas defined in claim 1 wherein the sealing means is biased into conta ct with the end faces of the adjacent radial partitions by adjustable spring means fixedto theimperforate portion of the end plate. I V

4. Regenerative heat exchange apparatus as defined in T claim 1 wherein the sealingmeans is biasedintocontact with the end faces of the radial partitions by means responsive to fluid pressure. I V g 7 5. Regenerative heat-exchange'apparatus as defined in a claim 1 wherein the sealing means is biased into contact a with the end faces of theradial partitions by magnetic 'field producing means supported by the sealingmeans.

- 6. Regenerative heat exchange apparatus having a rotor including a cylindrical shell joined to a rotor post by radial partitions "forming compartments that carry heat transfer material, a housing surrounding the rotor and provided opposite the latter with end plates formed with imperforate portions between circumferentially spaced apertures which permit heating gases and air to flow to and through the:rotor; axially movable sealing means adapted to preclude fluid flow between the imperforate portion of the end plate and adjacent end edges of the radial partitions, said sealing means including a radially extending channel portion supported by the end plate pivotally supporting a hooked portion of a horizontal sealing plate whereby a quantity of fluid in said channel will 'imme'rse the hooked portion of the sealing plate to preclude fluid flow therebetween.

7. Regenerative heat exchange apparatus as defined in claim 6 wherein the horizontal sealing plate extends circumferentially a distance greater than the distance between adjacent radial partitions.

8. Regenerative heat exchange apparatus having a rotor including a cylindrical shell joined to a rotor post by radial partitions forming compartments that carry heat transfer material, a housing surrounding .the rotor and apertures which permit heating gases and air to flow to a and through the rotor; axially movable sealing means adapted to preclude fluid flowbetween the imperforate portion of the end plate and adjacent end edges of the radial partitions, said sealing means including a radially extending channel portion supported by the end plate pivotally supporting a leading edge of a horizontal sealing plate, and means adapted to bias the trailing edge of said sealing plateinto contact with end edges of the radial partitions.

9. Regenerative heat exchange apparatus as defined in claim 8 wherein the means adapted to bias the sealing plate into contact with the radial partitions provides -its own magnetic field.

References Cited in the file of this patent UNITED STATES PATENTS 1,088,412 France Sept. 8, 1954- 

